Most people seem to have good results with Pool Filter sand and you may want to compare the cost of Pool Filter sand from a local pool supply shop vs what you are paying for, for silicia sand.
I have two Tom Barr recommended low tech tanks. One is a 5 gallon. It has Seachem Onyx sand capped over, mulm, peat, and leonardite. Plants are doing really well and growing like weeds. No algae whatsoever - 100% No Joke.
I have 3 gallon low tech tank at work. Tahitian Moon Sand capped over mulm, peat, and leonardite. Plants are also growing like weeds. I only had diatom algae in that one and as soon as I threw in one Amano Shrimp, the diatom algae seemed to disappear as quickly as it appeared.